Sorghum is an important cereal crop that originated in Africa. Sorghum is not well known as a dye plant in Europe, but it is used in Africa to dye leather and fabric. Tellem wool textiles from Mali and other parts of Africa dating to the 11th century were dyed using Sorghum leaves. The red sheaths are boiled, sometimes with the addition of an alkali. Adding iron sulphate produces a black colour, alum produces an olive colour, potash a tan colour and tin a green colour.